Activity of Certain Vit. B 12 Analogues in the Chick. ∗

Abstract

Summary

Activity of various vit. B₁₂ analogues was determined in young chicks fed a corn-soybean oil meal diet high in fat. The presence of cyanide in the molecule is not necessary for full vit. B₁₂ activity in the chick since acetato-, chloro-, nitro-, and sulfatoco-balamin had activities equal to that of vit. B₁₂ when fed or injected. Factor B had no vit. B₁₂-like activity nor any antagonistic action. The 5-hydroxy analogue of vit. B₁₂ had about one-tenth to one-third of the activity of vit. B₁₂.